Furnace for burning bagasse



(No Model.) 3 Sheets-Sheet 1. J. B. DUNN.

FURNACE FOR BURNING BAGASSE.

No. 364,228. Patented June 7, 1887.

WITNESSES INVENTOR (No Model.) 3 Sheets-Sheet 2. J. B. DUNN.

FURNACE FOB. BURNING BAGASSE.

Patented June 7, 1887.

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UNITED STATES PATENT ()rrrcn.

JAMEs B. DUNN, on NEW ORLEANS, LOUISIANA.

FURNACE FOR BURNING BAGASSE.

SPECIFICATION forming part of Letters Patent No. 364,228, dated June '7, 1887.

Application filed March 22, 1887. Serial No. 231,960. (No model.)

To all whom it may concern.-

Be it known that I, JAMES B. DUNN, 0 New Orleans, Louisiana, have invented certain new and useful Improvements in Furnaces for Burning Bagasse and other Green Fuel, of which the-following is a specification.

My invention consists, primarily, of a plan for setting boilers for utilizing bagasse, sawdust, or other green fuel under the boilers; and in carrying out my invention I employ a furnace withou t grate-bars, but having tuyercs and a suitable blower or artificial blast, and locate the furnace immediately beneath the boilers. Furnaces having tuyeres and blast apparatushave been constructed to burn ba-' gasse without grate-bars; but such furnaces have invariably been located at one side or at one end of the boilers and the gases or products of combustion passed through aheatingchamber, or mixing-chamber, as it is more commonly called, before coming in contact with the boilers. The theory has been that the different gases or vapors generated bythe products of combustion had to be heated or mixed in an intermediate chamber in order to produce any economical practical results. I have discovered that the mixing chamber or passage between the furnace and boiler is superfluous, and that better results may be obtained by setting the blast-furnace without .grate'bars immediately beneath the boilers, as

in my improved plan. I

My invention also contemplates certain important improvements in structural arrange ment and details, all of which will be understood from the following description.

In the accompanying drawings, Figure 1 is a longitudinal vertical section on the line 1 1 of Fig. 2; Fig. 2, a transverse section on the line 2 2 of Fig. 1; and Fig. 3, a horizontal section showing the ground plan on the line at front and rear in the brickwork.

The f urnace A,which is without grate-bars, has a closedhcarth, and is provided with suitable tuyercs and blast apparatus, is located immediately under the front of the boilers, being arranged transversely thereunder.

B Breprescnt ordinary ash-doors at the opposite ends of the furnace. In the walls surrounding the furnace are constructed blastchambers D, which are kept filled with compressed air by pipes D,commuuicating with a suitable power-driven blower,D Tuyeres O extend from the blast-chambers to the interior of the furnace, and are preferably arranged as seen in Fig. 2that is, the tuyercs are arranged in a solid bank nearest the bottom of the furnace; but commencing with, say, the fourth or fifth row, they are arranged in two pyramidal forms on each side of the furnace, for a purpose presently described.

In the front wall of the furnace a number of taps or pipes, E, are provided,'one opposite each tuyere C. These taps are normally closed by suitable plugsor caps, which may be removed for theinsertion of cleaning-rods,which may be passed through each opening and through the tuyereopposite it, to clean out and keep the tuyercs open.

At the rear of the furnace a transverse pas- Sage-way, F, is formed in the masonry of the furnace, and in the wall of this passage are similar openings, E, opposite the tuyercs G. The passage F is made sufficiently large to pen mit a workman to enter for the purpose of cleaning out the tuyercs on that side of the furnace. One or more doors, A, may be provided in the end and side walls of the furnace for the purpose of introducing wood-or coal,should it be desired to use such fuel. The products of combustion pass up into contact with the boilers and over the arch G, formed by the masonry covering thetransverse passage F. At one or both sidesof the fiat top 9 of this arch are arranged doors H, for the removal of any ashes that may accumulate thereon. At the rear of the arch G is a chamber, L, in

which ashes carried over by the draft will be N represents a bridge-wall under the rear ends of the boilers, to regulate the quantity of heat to be let into the boiler-fines, while a indicates a space left between the ends of the boilers and the end wall of the masonry. A small door, 0, may be provided at this end of the furnace, through which the flames returning into the boiler-fines may be observed. The tops of the boilers and the spaces between them and between the outside boilers and the masonry are protected by a jacket or cover, P, as seen more specially in Fig. 2. The flames from the furnace will pass the entirelength of the boiler in contact therewith, and then through the boiler-fines, should flued boilers be used, to the chimney NV.

The bagasse or green fuel may be fed to the furnace by means of an endless belt, Q, which delivers the fuel into a hopper having a bottom of an inverted-V shape in crosssection, so that the fuel is divided about equally as delivered to the hopper, one portion passing through afeeding-aperture, S, between the two right-hand boilers over one end of the furnace, and the other to a similar aperture between the two left-hand boilers over the opposite end of the furnace. The pyramidal arrangement of the tuyeres before mentioned is made with reference to these feeding-aperturesthat is, the apexes of the pyramids of tuyeres are arranged in line with the feeders.

When the bagasse or other wet fuel falls from the feeder or hopper, the greatest number of tuyeres will act upon it in the line of feed where the greatest mass of fuel is to be operated upon, and by arranging the tuyeres in a pyramidal form the fuel which tends to accumulate on the hearth in pyramidal piles will be acted upon at different points in pro portion to the mass of the fuel. I thus avoid the unnecessaryintroduction of air into the furnace at points where it is not needed.

T indicates an ordinary steam-drum arranged transversely above the boilers.

In each feed chute or aperture is arranged a valve or damper, which is normally kept closed by a weighted projecting arm, 8, An accumulation of fuel sufficient to overcome the gravity of the valve depresses it and admits the fuel to the furnace.

In the organization described it will be perceived that the furnace is located directly beneath the front ends of the boilers, and that the flames or products of combustion rise from the furnace immediately against the boilers and travel their entire length in contact with them. I have found that with such a construction better results are obtained than with the old plan of providing a mixing or heating chamber for the products of combustion. The structure is very much simpler and less expensive than the old plan, as the arrangement is more compact, the necessary amount of masonry very much reduced, and the brick-work passage or mixing-chamber between the furnace and boiler is dispensed with.

My improved organization possesses the very i mportant advantage, among other things, that by increasing the length of the furnace additional boilers may be arranged in the nest and additional feeding-apertures may be provided between the boilers. For instance, by doubling the width of the plant as viewed in crosssectiou in Fig. 2, four additional boilers may be employed, in which event I prefer to provide two additional feeding-apertures and have four pyramids of tuyeres on each side of the furnace.

In establishing a plant the furnace A might be made of sufficient length to accommodate more boilers than are actually needed, and then additional boilers could be added should occasion require.

The fact of being able to heat a number of boilers from the same furnace is, I repeat, an important matter, and one which willbe readily appreciated when it is understood. \Vhere the furnace is located to one side of the boilers, only about three boilers to each furnace can be employed with advantage.

\Vith the particular organization illustrated the tuyeres may be cleaned from time to time, whenever desired, without in any manner interrupting the working of the furnace. This is a very importantmatter, and results in great economy in time, labor, and fuel.

Thetuyercs, as will be perceived from Fig. 3, are preferably tapering, being widest at the blast-chambers. The size of the tuyeres where they open into the furnace may be, say, threefourths of an inch in diameter. I prefer to make them of such a size that they will be sufficient to throw the blast well into the center of the furnace without injecting an unnecessary amount of cold air. 7

I am aware that furnaces having ordinary grate-bars, or perforated hearths, or arched skeleton hearths operating after the manner of grate-bar furnaces, have been placed under boilers, and that it has been attempted to burn green fuel in them. I do not claim any such subject-matter;

I claim as my invention-- 1. In a furnace for. burning bagasse and other like fuel, the combination of the frame or masonry, a nest of boilers mounted therein, and a furnace, A, arranged transversely immediately beneath the boilers, said furnace being without grate-bars, but having tuyeres and suitable blast apparatus, substantially as and for the purpose set forth.

2. In a furnace for burning bagasse and other like fuel, the combination of the frame or masonry, a nest of boilers mounted therein in substantially the same horizontal plane, a furnace having a length in excess of its width, arranged transversely immediately beneath the boilers, said furnace being without gratebars, but having tuyeres and suitable blast apparatus,and feeding chutes or apertures arranged to deliver the green fuel between the boilers and into the furnace at different points, substantially as and for the purpose set forth.

3. In a furnace for burning bagasse and other like fuel, the combination of the frame or masonry, the boilers mounted therein, a

- furnace without grate-bars arranged immediately beneath the boilers, a feed-chute for delivering the green fuelinto thefurnaee, tuyeres in the wall of the furnace, arranged in a pyramidal form in line with the fall of the fuelsupply, and suitable blast apparatus for injecting air through the tuyeres, substantially as and for the purpose set forth.

4. In a furnace for burning bagasse and other like fuel, the combination of the frame or masonry, a nest of boilers mounted therein in substantially the same horizontal plane, a furnace without grate-bars arranged immediately beneath the boiler, two or more feedchutes for delivering the green fuel into the furnace at different points, tuyeres in the opposite wall arranged on each side in pyramidal form in line with the feed, and suitable blast apparatus, substantially as and for the purpose set forth.

5. In a furnace for burning bagasse and other like fuel, the combination of the frame or masonry, a nest of boilers mounted therein, a feed-hopper having an inverted-V-shaped bottom, and feed-chutes to which the green fuel delivered to the hopper is directed by the inclined sides of the hopper-bottom, the chutes being arranged to deliver the feed between pairs of boilers, the furnace A, without gratebars and having tuyeres, and suitable blast apparatus arranged immediately beneath the boilers, substantially as and for the purpose set forth. I

6. The combination of the furnace A, a blastchamber formed in the wall thereof, tuyeres leading from the blast-chamber into the furnace, and taps or cleaning-apertures extending from the outer wall of the furnace to the blastchamber, each. of said taps being arranged in line with a tuyere, whereby the tuyeres may be cleaned without slowing down the furnace.

7 The combination of the furnace A, the blast-chamber in the wall thereof, the tuyeres leading from the blast-chamber to the furnace, the transverse passage way F, and taps or openings in the walls of said passage-way, each tap being arranged opposite a tuyere in the furnace-wall, whereby the tuyeres on that side of the furnace may be cleaned without slowing down the fire, substantially as and for the purpose set forth. 7 f

8; The combination of the furnace, the blastehamber formed in the wall thereof, the conically-shaped tuyeres having their largest opening next the blast-furnace, and the cleaning taps or apertures extending from the opposite wall of the blast-chamber to the exterior of the furnace, substantially as and for the purpose set forth.

9. The combination of the frame or masonry, the nest of flue-boilers mounted therein, the furnace A, without grate bars and having tuyeres, a suitable blast apparatus arranged immediately under the boilers, the masonry arch in which the transverse passage is arranged, the blast-furnace, and tuycre-cleaning openings in the walls of the furnace, the ashreceptacle in the rear of the arch, doors for withdrawing the ashes from the reeeptacl e, the

-mud-drum and its support arranged in rear of the ash-chamber, and fuel-feeding devices for supplying the green fuel to the furnace at more than one point.

t In testimony whereof I have hereunto subscribed myname.

JAMES B. DUNN. 

